hals/camera/QemuClient.cpp

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * Contains implementation of classes that encapsulate connection to camera
 * services in the emulator via qemu pipe.
 */

#define LOG_NDEBUG 0
#define LOG_TAG "EmulatedCamera_QemuClient"
#include "QemuClient.h"
#include <log/log.h>
#include "EmulatedCamera.h"

#define LOG_QUERIES 0
#if LOG_QUERIES
#define LOGQ(...) ALOGD(__VA_ARGS__)
#else
#define LOGQ(...) (void(0))

#endif  // LOG_QUERIES
namespace android {

/****************************************************************************
 * Qemu query
 ***************************************************************************/

QemuQuery::QemuQuery()
    : mQuery(mQueryPrealloc),
      mQueryDeliveryStatus(NO_ERROR),
      mReplyBuffer(NULL),
      mReplyData(NULL),
      mReplySize(0),
      mReplyDataSize(0),
      mReplyStatus(0) {
  *mQuery = '\0';
}

QemuQuery::QemuQuery(const char* query_string)
    : mQuery(mQueryPrealloc),
      mQueryDeliveryStatus(NO_ERROR),
      mReplyBuffer(NULL),
      mReplyData(NULL),
      mReplySize(0),
      mReplyDataSize(0),
      mReplyStatus(0) {
  mQueryDeliveryStatus = QemuQuery::createQuery(query_string, NULL);
}

QemuQuery::QemuQuery(const char* query_name, const char* query_param)
    : mQuery(mQueryPrealloc),
      mQueryDeliveryStatus(NO_ERROR),
      mReplyBuffer(NULL),
      mReplyData(NULL),
      mReplySize(0),
      mReplyDataSize(0),
      mReplyStatus(0) {
  mQueryDeliveryStatus = QemuQuery::createQuery(query_name, query_param);
}

QemuQuery::~QemuQuery() { QemuQuery::resetQuery(); }

status_t QemuQuery::createQuery(const char* name, const char* param) {
  /* Reset from the previous use. */
  resetQuery();

  /* Query name cannot be NULL or an empty string. */
  if (name == NULL || *name == '\0') {
    ALOGE("%s: NULL or an empty string is passed as query name.", __FUNCTION__);
    mQueryDeliveryStatus = EINVAL;
    return EINVAL;
  }

  const size_t name_len = strlen(name);
  const size_t param_len = (param != NULL) ? strlen(param) : 0;
  const size_t required = strlen(name) + (param_len ? (param_len + 2) : 1);

  if (required > sizeof(mQueryPrealloc)) {
    /* Preallocated buffer was too small. Allocate a bigger query buffer. */
    mQuery = new char[required];
    if (mQuery == NULL) {
      ALOGE("%s: Unable to allocate %zu bytes for query buffer", __FUNCTION__,
            required);
      mQueryDeliveryStatus = ENOMEM;
      return ENOMEM;
    }
  }

  /* At this point mQuery buffer is big enough for the query. */
  if (param_len) {
    sprintf(mQuery, "%s %s", name, param);
  } else {
    memcpy(mQuery, name, name_len + 1);
  }

  return NO_ERROR;
}

status_t QemuQuery::completeQuery(status_t status) {
  /* Save query completion status. */
  mQueryDeliveryStatus = status;
  if (mQueryDeliveryStatus != NO_ERROR) {
    return mQueryDeliveryStatus;
  }

  /* Make sure reply buffer contains at least 'ok', or 'ko'.
   * Note that 'ok', or 'ko' prefixes are always 3 characters long: in case
   * there are more data in the reply, that data will be separated from
   * 'ok'/'ko' with a ':'. If there is no more data in the reply, the prefix
   * will be
   * zero-terminated, and the terminator will be inculded in the reply. */
  if (mReplyBuffer == NULL || mReplySize < 3) {
    ALOGE("%s: Invalid reply to the query", __FUNCTION__);
    mQueryDeliveryStatus = EINVAL;
    return EINVAL;
  }

  /* Lets see the reply status. */
  if (!memcmp(mReplyBuffer, "ok", 2)) {
    mReplyStatus = 1;
  } else if (!memcmp(mReplyBuffer, "ko", 2)) {
    mReplyStatus = 0;
  } else {
    ALOGE("%s: Invalid query reply: '%s'", __FUNCTION__, mReplyBuffer);
    mQueryDeliveryStatus = EINVAL;
    return EINVAL;
  }

  /* Lets see if there are reply data that follow. */
  if (mReplySize > 3) {
    /* There are extra data. Make sure they are separated from the status
     * with a ':' */
    if (mReplyBuffer[2] != ':') {
      ALOGE("%s: Invalid query reply: '%s'", __FUNCTION__, mReplyBuffer);
      mQueryDeliveryStatus = EINVAL;
      return EINVAL;
    }
    mReplyData = mReplyBuffer + 3;
    mReplyDataSize = mReplySize - 3;
  } else {
    /* Make sure reply buffer containing just 'ok'/'ko' ends with
     * zero-terminator. */
    if (mReplyBuffer[2] != '\0') {
      ALOGE("%s: Invalid query reply: '%s'", __FUNCTION__, mReplyBuffer);
      mQueryDeliveryStatus = EINVAL;
      return EINVAL;
    }
  }

  return NO_ERROR;
}

void QemuQuery::resetQuery() {
  if (mQuery != NULL && mQuery != mQueryPrealloc) {
    delete[] mQuery;
  }
  mQuery = mQueryPrealloc;
  mQueryDeliveryStatus = NO_ERROR;
  if (mReplyBuffer != NULL) {
    free(mReplyBuffer);
    mReplyBuffer = NULL;
  }
  mReplyData = NULL;
  mReplySize = mReplyDataSize = 0;
  mReplyStatus = 0;
}

/****************************************************************************
 * Qemu client base
 ***************************************************************************/

/* Camera service name. */
const char QemuClient::mCameraServiceName[] = "camera";

QemuClient::QemuClient() : mPipeFD(-1) {}

QemuClient::~QemuClient() {
  if (mPipeFD >= 0) {
    close(mPipeFD);
  }
}

/****************************************************************************
 * Qemu client API
 ***************************************************************************/

status_t QemuClient::connectClient(const char* param) {
  ALOGV("%s: '%s'", __FUNCTION__, param ? param : "");

  /* Make sure that client is not connected already. */
  if (mPipeFD >= 0) {
    ALOGE("%s: Qemu client is already connected", __FUNCTION__);
    return EINVAL;
  }

  /* Select one of the two: 'factory', or 'emulated camera' service */
  if (param == NULL || *param == '\0') {
    /* No parameters: connect to the factory service. */
    char pipe_name[512];
    snprintf(pipe_name, sizeof(pipe_name), "qemud:%s", mCameraServiceName);
    mPipeFD = qemu_pipe_open(pipe_name);
  } else {
    /* One extra char ':' that separates service name and parameters + six
     * characters for 'qemud:'. This is required by qemu pipe protocol. */
    char* connection_str =
        new char[strlen(mCameraServiceName) + strlen(param) + 8];
    sprintf(connection_str, "qemud:%s:%s", mCameraServiceName, param);

    mPipeFD = qemu_pipe_open(connection_str);
    delete[] connection_str;
  }
  if (mPipeFD < 0) {
    ALOGE("%s: Unable to connect to the camera service '%s': %s", __FUNCTION__,
          param ? param : "Factory", strerror(errno));
    return errno ? errno : EINVAL;
  }

  return NO_ERROR;
}

void QemuClient::disconnectClient() {
  ALOGV("%s", __FUNCTION__);

  if (mPipeFD >= 0) {
    close(mPipeFD);
    mPipeFD = -1;
  }
}

status_t QemuClient::sendMessage(const void* data, size_t data_size) {
  if (mPipeFD < 0) {
    ALOGE("%s: Qemu client is not connected", __FUNCTION__);
    return EINVAL;
  }

  /* Note that we don't use here qemud_client_send, since with qemu pipes we
   * don't need to provide payload size prior to payload when we're writing to
   * the pipe. So, we can use simple write, and qemu pipe will take care of the
   * rest, calling the receiving end with the number of bytes transferred. */
  const size_t written = qemud_fd_write(mPipeFD, data, data_size);
  if (written == data_size) {
    return NO_ERROR;
  } else {
    ALOGE("%s: Error sending data via qemu pipe: '%s'", __FUNCTION__,
          strerror(errno));
    return errno ? errno : EIO;
  }
}

status_t QemuClient::receiveMessage(void** data, size_t* data_size) {
  *data = NULL;
  *data_size = 0;

  if (mPipeFD < 0) {
    ALOGE("%s: Qemu client is not connected", __FUNCTION__);
    return EINVAL;
  }

  /* The way the service replies to a query, it sends payload size first, and
   * then it sends the payload itself. Note that payload size is sent as a
   * string, containing 8 characters representing a hexadecimal payload size
   * value. Note also, that the string doesn't contain zero-terminator. */
  size_t payload_size;
  char payload_size_str[9];
  int rd_res = qemud_fd_read(mPipeFD, payload_size_str, 8);
  if (rd_res != 8) {
    ALOGE("%s: Unable to obtain payload size: %s", __FUNCTION__,
          strerror(errno));
    return errno ? errno : EIO;
  }

  /* Convert payload size. */
  errno = 0;
  payload_size_str[8] = '\0';
  payload_size = strtol(payload_size_str, NULL, 16);
  if (errno) {
    ALOGE("%s: Invalid payload size '%s'", __FUNCTION__, payload_size_str);
    return EIO;
  }

  /* Allocate payload data buffer, and read the payload there. */
  *data = malloc(payload_size);
  if (*data == NULL) {
    ALOGE("%s: Unable to allocate %zu bytes payload buffer", __FUNCTION__,
          payload_size);
    return ENOMEM;
  }
  rd_res = qemud_fd_read(mPipeFD, *data, payload_size);
  if (static_cast<size_t>(rd_res) == payload_size) {
    *data_size = payload_size;
    return NO_ERROR;
  } else {
    ALOGE("%s: Read size %d doesnt match expected payload size %zu: %s",
          __FUNCTION__, rd_res, payload_size, strerror(errno));
    free(*data);
    *data = NULL;
    return errno ? errno : EIO;
  }
}

status_t QemuClient::doQuery(QemuQuery* query) {
  /* Make sure that query has been successfuly constructed. */
  if (query->mQueryDeliveryStatus != NO_ERROR) {
    ALOGE("%s: Query is invalid", __FUNCTION__);
    return query->mQueryDeliveryStatus;
  }

  LOGQ("Send query '%s'", query->mQuery);

  /* Send the query. */
  status_t res = sendMessage(query->mQuery, strlen(query->mQuery) + 1);
  if (res == NO_ERROR) {
    /* Read the response. */
    res = receiveMessage(reinterpret_cast<void**>(&query->mReplyBuffer),
                         &query->mReplySize);
    if (res == NO_ERROR) {
      LOGQ("Response to query '%s': Status = '%.2s', %d bytes in response",
           query->mQuery, query->mReplyBuffer, query->mReplySize);
    } else {
      ALOGE("%s Response to query '%s' has failed: %s", __FUNCTION__,
            query->mQuery, strerror(res));
    }
  } else {
    ALOGE("%s: Send query '%s' failed: %s", __FUNCTION__, query->mQuery,
          strerror(res));
  }

  /* Complete the query, and return its completion handling status. */
  const status_t res1 = query->completeQuery(res);
  ALOGE_IF(res1 != NO_ERROR && res1 != res,
           "%s: Error %d in query '%s' completion", __FUNCTION__, res1,
           query->mQuery);
  return res1;
}

/****************************************************************************
 * Qemu client for the 'factory' service.
 ***************************************************************************/

/*
 * Factory service queries.
 */

/* Queries list of cameras connected to the host. */
const char FactoryQemuClient::mQueryList[] = "list";

FactoryQemuClient::FactoryQemuClient() : QemuClient() {}

FactoryQemuClient::~FactoryQemuClient() {}

status_t FactoryQemuClient::listCameras(char** list) {
  ALOGV("%s", __FUNCTION__);

  QemuQuery query(mQueryList);
  if (doQuery(&query) || !query.isQuerySucceeded()) {
    ALOGE("%s: List cameras query failed: %s", __FUNCTION__,
          query.mReplyData ? query.mReplyData : "No error message");
    return query.getCompletionStatus();
  }

  /* Make sure there is a list returned. */
  if (query.mReplyDataSize == 0) {
    ALOGE("%s: No camera list is returned.", __FUNCTION__);
    return EINVAL;
  }

  /* Copy the list over. */
  *list = (char*)malloc(query.mReplyDataSize);
  if (*list != NULL) {
    memcpy(*list, query.mReplyData, query.mReplyDataSize);
    ALOGD("Emulated camera list: %s", *list);
    return NO_ERROR;
  } else {
    ALOGE("%s: Unable to allocate %zu bytes", __FUNCTION__,
          query.mReplyDataSize);
    return ENOMEM;
  }
}

/****************************************************************************
 * Qemu client for an 'emulated camera' service.
 ***************************************************************************/

/*
 * Emulated camera queries
 */

/* Connect to the camera device. */
const char CameraQemuClient::mQueryConnect[] = "connect";
/* Disconect from the camera device. */
const char CameraQemuClient::mQueryDisconnect[] = "disconnect";
/* Start capturing video from the camera device. */
const char CameraQemuClient::mQueryStart[] = "start";
/* Stop capturing video from the camera device. */
const char CameraQemuClient::mQueryStop[] = "stop";
/* Get next video frame from the camera device. */
const char CameraQemuClient::mQueryFrame[] = "frame";

CameraQemuClient::CameraQemuClient() : QemuClient() {}

CameraQemuClient::~CameraQemuClient() {}

status_t CameraQemuClient::queryConnect() {
  ALOGV("%s", __FUNCTION__);

  QemuQuery query(mQueryConnect);
  doQuery(&query);
  const status_t res = query.getCompletionStatus();
  ALOGE_IF(res != NO_ERROR, "%s: Query failed: %s", __FUNCTION__,
           query.mReplyData ? query.mReplyData : "No error message");
  return res;
}

status_t CameraQemuClient::queryDisconnect() {
  ALOGV("%s", __FUNCTION__);

  QemuQuery query(mQueryDisconnect);
  doQuery(&query);
  const status_t res = query.getCompletionStatus();
  ALOGE_IF(res != NO_ERROR, "%s: Query failed: %s", __FUNCTION__,
           query.mReplyData ? query.mReplyData : "No error message");
  return res;
}

status_t CameraQemuClient::queryStart(uint32_t pixel_format, int width,
                                      int height) {
  ALOGV("%s", __FUNCTION__);

  char query_str[256];
  snprintf(query_str, sizeof(query_str), "%s dim=%dx%d pix=%d", mQueryStart,
           width, height, pixel_format);
  QemuQuery query(query_str);
  doQuery(&query);
  const status_t res = query.getCompletionStatus();
  ALOGE_IF(res != NO_ERROR, "%s: Query failed: %s", __FUNCTION__,
           query.mReplyData ? query.mReplyData : "No error message");
  return res;
}

status_t CameraQemuClient::queryStop() {
  ALOGV("%s", __FUNCTION__);

  QemuQuery query(mQueryStop);
  doQuery(&query);
  const status_t res = query.getCompletionStatus();
  ALOGE_IF(res != NO_ERROR, "%s: Query failed: %s", __FUNCTION__,
           query.mReplyData ? query.mReplyData : "No error message");
  return res;
}

status_t CameraQemuClient::queryFrame(void* vframe, void* pframe,
                                      size_t vframe_size, size_t pframe_size,
                                      float r_scale, float g_scale,
                                      float b_scale, float exposure_comp) {
  ALOGV("%s", __FUNCTION__);

  char query_str[256];
  snprintf(query_str, sizeof(query_str),
           "%s video=%zu preview=%zu whiteb=%g,%g,%g expcomp=%g", mQueryFrame,
           (vframe && vframe_size) ? vframe_size : 0,
           (pframe && pframe_size) ? pframe_size : 0, r_scale, g_scale, b_scale,
           exposure_comp);
  QemuQuery query(query_str);
  doQuery(&query);
  const status_t res = query.getCompletionStatus();
  if (res != NO_ERROR) {
    ALOGE("%s: Query failed: %s", __FUNCTION__,
          query.mReplyData ? query.mReplyData : "No error message");
    return res;
  }

  /* Copy requested frames. */
  size_t cur_offset = 0;
  const uint8_t* frame = reinterpret_cast<const uint8_t*>(query.mReplyData);
  /* Video frame is always first. */
  if (vframe != NULL && vframe_size != 0) {
    /* Make sure that video frame is in. */
    if ((query.mReplyDataSize - cur_offset) >= vframe_size) {
      memcpy(vframe, frame, vframe_size);
      cur_offset += vframe_size;
    } else {
      ALOGE("%s: Reply %zu bytes is to small to contain %zu bytes video frame",
            __FUNCTION__, query.mReplyDataSize - cur_offset, vframe_size);
      return EINVAL;
    }
  }
  if (pframe != NULL && pframe_size != 0) {
    /* Make sure that preview frame is in. */
    if ((query.mReplyDataSize - cur_offset) >= pframe_size) {
      memcpy(pframe, frame + cur_offset, pframe_size);
      cur_offset += pframe_size;
    } else {
      ALOGE(
          "%s: Reply %zu bytes is to small to contain %zu bytes preview frame",
          __FUNCTION__, query.mReplyDataSize - cur_offset, pframe_size);
      return EINVAL;
    }
  }

  return NO_ERROR;
}

}; /* namespace android */